Originally Posted by HighandDry
With the stock exhaust, I could hardly hear it in the cabin.
Put on the Akrapovic Slip On and while it sounds nice outside, it's still pretty quiet in the cabin. I also expected it to get significantly louder past 4K, but it seems pretty constant. It seems that my other aftermarket exhausts (RSC on Aston, Europipe on Turbo, Porsche Sports Exhaust on Carrera) were much louder in the cabin.
Is the soundproofing that dense in the M3? Well I notice a big upgrade in sound if I go for the full Evolution?
Maybe I'm just forgetting how loud the other cars were. I've been driving my F430 a lot and it just screams past 4K. That car has stock exhaust, but Fabspeed headers/cats.
You'd be surprised how loud the car is outside.
Inside, yes, the sound deadening is surprisingly effective.
That said, the S65 makes enough noise that it drowns out most reasonable slip ons over 4000 rpm. The intake is quite loud, so you hear that.
The Evolution is louder, but at the expense of a LOT more noise in the low end. It's probably the least drone prone full system, but it can still be surprisingly loud at low RPMs.
If you want loud from the outside at high RPMs, get a valved exhaust or get a super ear piercingly loud exhaust.